The evergreen Serena Williams cannot picture an end date for her illustrious career after breaking another record at the US Open.

World number one Williams eclipsed Roger Federer for most grand-slam victories in the Open Era – 308 – with a 6-2 6-3 win over Yaroslava Shvedova in the fourth round on Monday.

And the 22-time major champion shows no signs of slowing down at the age of 34 as she basks in another milestone.

After overtaking men's star Federer, Williams told reporters: "I think it's really exciting. I just think winning 308 matches in general is pretty awesome. For that to be in a Grand Slam is pretty cool.

"It's a huge number. I think it's very significant actually. I think it's something that, you know, just really talks about the length of my career, in particular.

"I've been playing for a really long time, but also, given that consistency up there. That's something that I'm really proud of."

Pressed on her longevity, Williams – who will meet Simona Halep in the quarter-finals – added: "I think it just comes from a different place of the just love and really enjoying it. I definitely never thought I would be playing still.

"Now I don't really see when I'm going to stop because I'm just enjoying these moments out here, getting to break records that I didn't even know existed or I didn't even know was possible.